A cell connector, which is provided at least for one battery cell of an electrical energy store and which establishes the electrically conductive connection to an electric motor of an electric motor vehicle or of a hybrid vehicle or to further interconnected battery cells, has a region with a tapered cross section between its two contact ends, it additionally being possible for a permanent mechanical prestress to act on said tapered cross section.
In the event of a brief current flow which is increased owing to a short circuit, disconnection takes place at that point of the cell connector which has a weakened cross section and constitutes a fuse.
A battery cell or a plurality of battery cells of a battery system, which battery cell or battery cells serve to drive electric motor vehicles or hybrid vehicles, can emit operating voltages of up to 600 V, via high-voltage paths, to a drive system when connected to a battery system in the charged state, in particular when using lithium-ion battery cells. In the event of a disturbance in a defective lithium-ion battery cell, current flows of up to 1000 A may briefly occur, these possibly leading to irreversible damage to the entire drive system and/or further lithium-ion battery cells which are interconnected in a cell composite. A damaged lithium-ion battery cell therefore has to be disconnected from the battery system by the shortest route in order to avoid consequential damage to an electrical energy store or to a drive system of an electric motor vehicle or of a hybrid vehicle.
DE 10 2008 043 946 A1 discloses a safety device for a rechargeable battery cell which has an electrode group which is arranged in an elastic cell sheathing and has at least one electrical connection. The safety device is designed, in principle, in such a way that a locking element is provided, which locking element locks at least one first electrical contact, which is associated with the electrical connection, in a releasable electrical connection to at least one second electrical contact, wherein the locking element is designed to release the releasable electrical connection in the event of an expansion in the cell sheathing due to a change in volume of the rechargeable battery cell during operation, in order to allow the second contact to be disconnected from the first contact.